Re:DeskNC - was CNC Pro 3x as fast as EMC??? NEW: PIC for controller?

Hi Larry,

Pretty good! You brought up the ICE *before* I posted the mail! As you
know, and others may or may not know, the 'F parts are electrically
erasable, MUCH easier to erase/program/try. How do you like the
Microchip ICD?

Alan KM6VV


Larry Edington wrote:

>
> > Larry,
> > What added cost is there to program the PIC? It
> > is obvious you have mastered PICs! A person going
> >with your suggestion now has to add more to his
> >plate.
>
> But you were advocating just a few messages ago to do it yourself to learn
> something!
>
> If you build your own programmer, very little additional cost other than
> time. Most 'non programmer' types can program in Basic rather quickly. Basic
> PIC compilers are cheap. If you want to learn assembly language
> programming, then it can all be practically free. You can also pick up the
> Microchip or Advanced Transdata 16F877 in circuit debugger / programmer (
> ICD ) for around $150. Or you can build that yourself too using the plans
> from www.epemag.com
>
> > I say build a simple controller capable of 6amps at
> > 60 volts per phase. The circuit has been around for 30 years!
> > It uses cheap chips and almost all Radio Shack parts. >Where can
> > you find such a diagram, you ask? Well look I have a >website TOO!
>
> The problems I see with your circuit is: (1) It's a Unipolar drive which
> costs a lot of torque the motor could otherwise produce. (2). It uses
> discrete logic ( flip flops and xor gates ) all of which are built into the
> L297 so why build it out of discrete logic? (3). It is an LR drive which
> means lots of power wasted as heat. (4). It has no current feedback so you
> can't drive the motors at optimum settings as a chopper drive can.
>
> By the time a novice electronics technician could build your circuit, they
> could put an L297 / L298 board together and have a better performing
> circuit.
>
> later,
> Larry E.